1. Field of the Invention
The present invention relates to an electric power steering apparatus, especially the electric power steering apparatus having a control housing built in the electric power steering apparatus.
2. Description of the Related Art
It is well known that there is an electric power steering apparatus to assist by applying the steering force created by an electric motor to a steering mechanism. Various sensors detect steering states of a steering wheel. By outputs from sensors, a controller controls the electric motor to assist the steering force to the steering mechanism, as shown in Tokkai 2003-267233 for example.
The conventional electric power steering apparatus shown in Tokkai 2003-267233 is equipped a controller accommodated in a control housing. The control housing is mounted on a side of the electric motor outside the electric power steering apparatus.
However, the conventional electric power steering apparatus can not be manufactured as a small apparatus, especially in radial direction of the electric motor, because the control housing is installed on the side of the electric motor.
Further in the conventional electric power steering apparatus shown in Tokkai 2003-267233, the controller has a plurality of electronic parts which are mounted on a square board. The board is fixed by bolts at four corners to the control housing. The bolts are mounted from a side where the electronic parts are mounted on the board.
However, in assembling work of this conventional electric power steering apparatus, required is attention for avoiding interference between the bolt itself or an assembling tool screwing the bolts and the electronic parts mounted on the board.